Webhook Signature Handling Vulnerability in OpenClaw by OpenClaw
CVE-2026-41351

6.3MEDIUM

Key Information:

Vendor

Openclaw

Status
Openclaw
Vendor
CVE Published:
23 April 2026

What is CVE-2026-41351?

A vulnerability exists in OpenClaw prior to version 2026.3.31 that allows attackers to bypass replay detection in webhook signature handling. This flaw occurs when Base64 and Base64URL encoded signatures are treated as separate requests, enabling attackers to re-encode Telnyx webhook signatures, effectively circumventing the protections meant to prevent replay attacks while still passing the validity checks for signatures.

Affected Version(s)

OpenClaw 0 < 2026.3.31

OpenClaw 2026.3.31

References

https://github.com/openclaw/openclaw/security/advisories/...
vendor-advisory
https://github.com/openclaw/openclaw/commit/ad77666054651...
patch
https://www.vulncheck.com/advisories/openclaw-webhook-rep...
third-party-advisory

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

AntAISecurityLab
.